Pipe thread protector



March i5, 1966 c. J. MA1-HERNE 3,240,232

PIPE THREAD PROTECTOR Filed July 27, 19s?. s sheets-sheet 1 Carrol J Maf/7eme INVENTOR.

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March 15, 1966 c. J. MATHERNE PIPE THREAD PROTECTOR s sheets-Sheet a Filed July 27 1962 Carrol J Maf/1eme INVENTOR. @16km BY m, 19mm March 15, 1966 c. J. MA1-HERNE PIPE THREAD PROTECTOR 3 Sheetsr-Sheet 5 Filed July 27, 1962 Fig. 6

Carrol u'. Mathe/'ne zNr/ENTOR.

www 5mm United States Patent O 3,240,232 PIPE THREAD PROTECTOR Carrol J. Mather-ue, 2709 W. Main St., Houma, La. Filed July 27, 1962, Ser. No. 212,961 Claims. (Cl. 13S- 96) This invention comprises a novel and useful thread protector and method of running well casing and more particularly pertains to the art of making up strings of well casing or tubing for inserting the latter in a well bore during well drilling or well servicing operations. In its broader aspects, this invention relates to a novel and improved means and method for applying a protective radially deformable and yieldable sleeve constrictively and compressively upon the exterior surface of a cylindrical article.

In the well drilling and servicing industry as in other fields of activity, the mounting costs of labor are becoming an increasingly important factor in determining whether the associated operation will involve a profit or loss. It is therefore extremely important to effect improvements and changes in operation which will reduce insofar as possible the labor required for a given operation as well as the time necessary to carry out the operation. It is therefore the primary purpose of this invention to provide a method and a construction which will reduce the requirements as to time and labor as much as possible in connection with the operation of making up and running in casing or tubing strings in a well bore.

A primary object of this invention is to provide a thread protector adapted to be quickly attached to or removed from the external threads at the end of a length of well casing or tubing in order to protect those threads during the handling of the pipe length when applying the pipe to or removing it from a casing or tubing string.

A further object of the invention is to provide a protector for pipe threads in accordance with the foregoing object which shall not obstruct the interior of the pipe or interfere with the passage of an internal gauge through the interior of the pipe section.

A further object of the invention is to provide a protector device in accordance with the foregoing objects in which the clamping means for securing the protector compressively and constrictively upon the external pipe threads of a section or length of pipe shall be protectively housed within the body and material of the protector itself thereby affording protection against deterioration of the clamping means as well as offering protection against injury to persons or objects adjacent to the protector.

Yet another purpose of the invention is to provide a protector in accordance with the foregoing objects which shall include therein provision for varying the constrictive action of the protector in order to readily adapt the latter to different sizes of pipe as Well as to compensate for wear in the protector itself during use.

Another important object of the invention is to provide a protector in accordance with the preceding objects which shall be quick and secure in its operation of locking the protector in place or releasing the protector from a threaded pipe end, and whereby the releasing operation may be effected from a position remote from the protector to thereby prevent the necessity for workmen placing their hands upon the protector or within portions of the latter.

Still another purpose of the invention is to provide a protector as set forth in the above mentioned objects which shall include a one-piece body of a resilient pliable or deformable material into which are Vincorporated reinforcing strands in a novel and improved manner.

Yet another purpose of the invention is to provide a method which will greatly facilitate the moving of pipe 3,240,232 Patented Mar. 15, 1966 ICC sections from a horizontal storage rack into vertical position for attachment to a string of casing or tubing for insertion into a well bore which will result in a saving of time, a reduction in the amount of labor required and will greatly minimize possible damage to the threaded ends of the pipe sections or injury to workmen adjacent thereto.

Still another object is to provide a protective sleeve of a yieldable material and having reinforcing, tensionable elements embedded therein for compressive embracing attachment to an article of a generally cylindrical conguration.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE l is a View partly in elevation and partly in vertical section showing a portion of a typical Well drilling or working installation incorporating therein the principles of this invention;

FIGURE 2 is a perspective view showing the thread protector of this invention in its locked or clamped position;

FIGURE 3 is a perspective view of the reinforcing elements removed from the body of the protector and with the locking means being in its released position;

FIGURE 4 is a fragmentary detail view in horizontal section through a portion of the protector of FIGURE 2 and showing in particular the disposition of the clamping or locking means and Iits association with the reinforcing elements embedded within the protector in the locked position of the latter;

FIGURES 5-7 are vertical transverse sectional views taken respectively upon the planes indicated by the section lines 5 5, 6-6 and 7*-7, respectively, of FIGURE 4 but upon an enlarged scale; and

FIGURE 8 is a detail View in vertical central section through a portion of the lower end of the pipe section being lifted as shown in FIGURE l and showing the protector in place and the movement of an internal gauge block through the pipe section.

Reference is made tirst to FIGURE 1 wherein the numeral 16 designates generally an oil well drilling or servicing rig having a 'drilling `or servicing platform 12 together with -a traveling block 14 by means of which lengths of casing or tubing pipes or sections 16 are removed from a horizontal pipe storage rack 18 into vertical position for attachment to a string of casing or pipe 20 disposed in a Well bore 22. Inasmuch as the details of this structure and operation are generally well known to those skilled in the art, a further description is deemed to Ibe unnecess-ary for an understanding of the principles of the invention set forth and claimed hereinafter.

In the moving of pipe from the storage rack 18 to a vertical position above the well bore in order that Ithe pipe may be applied to the string 20, it will be evident that the lower end of the pipe is dragged across the rack and across the platform 12 until it reaches a substantially vertical position. During this dragging operation owing to the heavy nature `of the pipe, the threads at the lower end thereof whereby the pipe section is to be secured to the string 20 are frequently damaged and burred. It has been customary heretofore to provide thread protectors for the threaded lower extremities, indicated at 24 in FIGURE 8, for the section 16 to prevent this damage thereto. However, such protectors although effective for this purpose, have the disadvantage usually that they require considerable time to apply or to remove from the pipe, and even when applied they frequently obstruct the .interior opening of the pipe.

Since it is well known that a smooth unobstructed interior is necessary for the pipe since it is frequently desirable to pass a string of tools or equipment through the pipe for various purposes, it is obvious that such obstructions will greatly interfere with this function. Therefore, it has become customary to pass an internal gauge indicated generally by the numeral 26 in FIGURE 8 through the length of pipe 16 from the upper to the lower endl thereof in order to make certain that the pipe is of uniform minimum diameter throughout its length and is unobstructed. Conventional protec-tors by their obstruction of the outlet -or lower end of the pipe frequently interfere with such travel of the gauge. Consequently, considerably greater time is required for applying and removing such protectors and to effect the necessary gauging operation before the pipe section can be lifted into a vertical suspended position over the string 20 to which it is to be attached.

The primary purpose of this inven-tion is to provide a pipe thread protector `and a method of running pipe which will effectively overcome the above mentioned difficulties, will greatly facilitate the ease of connecting the pipe sections to the string `and minimize damage to the pipe sections or injury to others during these operations.

The present invention makes use of a novel and improve-d construction of pipe protector indicated generally by the numeral 30. As will be apparent from FIGURE 8, this pipe protector in its applied position effectively covers, embraces `and protects the threaded lower lextremity 24 of a pipe but offers no obstruction whatsoever to the interior of the pipe and the lower end thereof. Consequently, as shown in FIGURE 8, an internal gauge 26 may be freely slid longitudinally through the pipe under the influence of gravity and will emerge from the lower end thereof without interference by the protector. Thus, the pipe protector of this invention greatly facilitates the normal gauging operation of the pipe sections prior to their attachment to the pipe string 20.

Referring next primarily to FIGURE 2 of the drawing it will be observed that the protector 30 consists of a generally annular body 32 of C-shaped configuration which is open at its ends to provide an entrance slot 34 of varying width therebetween. The body 32 is of any desired material of a resilient character such as rubber, a suitable plastic or the like. As will now be best apparent from FIGURES 3-4, the body 32 has embedded therein a reinforcing and tensioning `assembly designated generally by the numeral 38 and shown in FIGURE 3. This assembly consists of a plurality of tensioning members 40` which may be in the form of strands of suitable cables. Thus, the members m-ay be of nylon or other synthetic material, having some degree of 'elastici-ty therein. In other instances, however, relatively non-elastic members such as steel cables may be employed for this purpose. As shown in FIGURE 4, the reinforcing tension members are disposed medially of the body and are embedded therein. However, in some instances these tensioning members may be disposed very closely adjacent to either the inner or outer peripheries of the arcuate C-shaped protector body.

A fastener is provided connected to the opposite ends of the tensioning members 40 of the reinforcing element 38 in order to controllably vary the opening 34 in the C- shaped body and thus effectively circumferentially constrict the body upon t-he threaded extremity 34 of the section 16. A convenient and preferred form of fastener for this purpose is shown in FIGURES 2-4 `and comprises a pair of brackets indicated generally by the numerals 42 and 44 and which respectively constitute anchor and latch lever brackets. Each of the brackets may consist of a plate-like steel member. Thus, the anchor bracket 42 may comprise a fla-t steel plate 46 having intermediate its ends a perpendicular upstanding flange 48 comprising an apertured lug. A T-shaped element consisting of a stem 50 externally threaded as at 52 is received through the apertured lug 48 and is provided with an adjustable locking nut 54 thereon. The other end of this member has a transverse tubular cross member 56 in which is pivotally mounted the web portion 58 of a U-shaped anchor link designated generally by the numeral 60. The latter has a pair of parallel arms 62 by which it is pivotally connected to the other component of the fastener.

The latch lever plate 44 likewise has a platelike base 64 with marginal upstanding side walls 66. Between the side walls there are provided a pair of parallel apertured ears 68 and a pivot pin 70 is secured in these ears and extends through the central tubular portion 72 of a latch lever 74.

The ends of the arms 62 of the anchor link are inturned and are received in bores 76 on the side of the latch lever 74 so that the anchor link is pivoted to the latch lever in an off-center relation with respect to the pivot 70.

A chain, cable or the like as at 80 is secured as by a member 82 to the extremity of the lever 74 to effect removal operation of this lever.

A slot 84 is formed in one side edge of the latch lever 74 and terminates in a diametrically enlarged aperture 86 therethrough. The purpose of this slot will be subsequently apparent.

The opposite or remote ends of the plates 46 and 64 are laterally reduced and terminate in cross arms as indicated at 88 and 90. The tension members 60 are secured to t-hese cross arms as by being looped or entrained thereover although it will be appreciated that they may be fastened thereto in any desired manner.

It will be noted from FIGURE 3 that the anchor and latch lever brackets 42 and 44 are actuated from end to end thereof so that, as shown in FIGURE 4, they may be uniformly embedded in the material of the body 32 of 4the protector. That end of the protector in which is embedded the anchor bracket 42 is provided with a bore 92 which opens into the slot 34. The lug 48 of the anchor bracket extends into this bore so that the externally threaded stem 52 `and the lock nut 54 may be received in the bore and may be accessible from the open outer end of the latter for adjusting the lock nut upon the stem and thus adjusting the overall length of the two fastener components 42 and 44 and thus regulating or adjusting the opening 34 between the opposite ends of the protector body. As shown in FIGURE 4, and in FIGURE 5, that end of the bore 91 which opens the slot 34 is laterally enlarged as at 92 to movably receive therein the anchor link 62 as the latter pivots about its bight portion 58 in the tubular cross member S6.

In 'a similar manner, the latch bracket 44 is likewise embedded in the material at the outer side of the opening 34. As shown best in FIGURE 6, the exterior surface of the protector body is provided with a circumferentially extending channel 94. The base plate 64 and the side walls 66 thereof are embedded in the bottom Iand side Walls of the channel to constitute a reinforcing member therefor. The apertured ears 68 project upwardly through this material into the channel and thus position the pivot pin 70 of the latch lever 74 in the channel itself. Owing to the overcenter relation of the pivotal -connection of the anchor link to the latch lever with respect to the connection of the latter upon the -apertured ears 68, a stable positioning of the yfastener in its locking position is obtained. In this position al1 of the parts of the device are fully recessed into the exterior surface of the protector except that the manual actuating member 80 wil) project therefrom.

As will be noted, the concave interior surface of the annular protector 30 may be threaded or grooved as `at 96 to conform to the threaded extremity 24 of the section 16.

In operation, the protector may be placed when in its expanded position `about the externally threaded lower end of pipe section 16 whereupon the latch lever 74 may be moved to its closed position in the channel 94. This will close or reduce the gap 34 between the ends of the protector thus causing the latter to compressibly grip and engage the exterior surface of the pipe. As will be noted,

the protector thus leaves the end of the pipe completely open and unobstructed. Owing to the over-center relation, as will be apparent from a comparison of FIGURE 3 with FIGURE 4, the tension applied to the reinforcing elements 40 will produce a stable closed or locked position of the fastener thereby securely retaining the protector `upon the pipe. When it is desired to remove the protector it is merely necessary for the user to pull the cord or cable 80 without it being necessary to insert the hands into proximity of the pipe.

The method of setting pipe in accordance with this invention is as follows:

With the series of pipe sections 16 disposed horizontally upon the storage rack 18, the protectors 30 are secured to the lower threaded extremity of each of the pipe sections. The internal gauge 26 is placed in the upper end of a `pipe section so that when the pipe is engaged by the block 14 of the rigging and lifted to the inclined position shown in FIGURE 1, the gauge will slide by gravity through the pipe to the lower end of the latter and will emerge from this lower end as suggested in FIGURE 8. This indicates that the pipe is of uniform minimum diameter and unobstructed throughout its length and thus is ready for use in the string of pipe to be set. From the position shown in FIGURE l, the pipe is limited to a freely suspended vertical position, whereupon lby actuation o f the 'cable 80 the protector is released from the pipe and the section 16 is then secured to the string of pipe 20 in the well bore.

It will thus be evident that a minimum amount of labor and time is required to effect the internal gauging and the making up of a string of pipe.

As will be not-ed in FIGURE l, there is provided a guy line 98 which is strung betwen the derrick 10 and the support rack 18. When the protector is removed from the depending end of this section 16 after the latter is lifted from the storage rack above the drilling platform 12, the slot 84 in the latch lever 74 is threaded upon the guy `line 98 and under the intiuence of gravity protector slides downwardly from the platform to the rack where it may be readily removed when its use is again desired.

The plurality of tensioning members are of great tensile strength and may be of a material possessing both resilience or elasticity as well as flexibility as in the case of nylon or other synthetic material or may be exible but with little elasticity as in the case of steel cables. Further, the tensioning members function as drawstrings effect a compressive engagement of the sleeve or ring 30 upon the article being embraced. For this purpose, the embedded members may Abe either bonded to or may possess a more or less limited slidability with reference to the material in which they are embedded.

Although in the illustrative embodiment of the invention the protector is of a generally annular C-shaped configuration with an entrance slot, it should be understood that the :invention .is not limited thereto, but comprehends within its scope other shapes and configurations as well as continuous and unbroken rings and sleeves. The essence of the invention resides in the broad concept of a sleeve or jacket of a pliable material having reinforcing and tensioning members embedded therein together with means for tensioning the members which act as drawstrings to constrict the protector body.

In a preferred form, the previously described anchor link 60 is a continuous rectangular frame or rod-like member hav-ing its ends joined and welded together, as upon one exposed side leg thereof, see FIGURE 3. This provides the maximum strength and prevents the anchor link from being accidentally disengaged from either the latch lever 74 or the cross member 56, thereby maintaining the continuity of the protector.

A very important and novel feature of this invention resides in the provision of the lug 48 and its association with the stem 52 and lock nut 54. This enables the protector to be set, or released, Iand the tension to be adjusted by merely manipulating the nut S4 ensuring against the possibility of failure of the gripping action or possible dropping `and loss of loose parts, a frequent source of failure of prior devices.

Further, the means for adjusting the tension of the drawstrings or strands, members 48, 52, 54, is incorporated for convenient handling into the fastener members 74, 68, 60 but could also be separate and independent therefrom.

Should for any reason the tension applied to the reinforcing elements 40 be insuicient, the nut 54 can be readily adjusted by a conventional wrench inserted in the bore 91 and turning the lock nut until suicient tension is produced to obtain the desired gripping and holding power of the protector.

The foregoing is considered as illustrative only of the principles lof the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, if is not desired to limit the invention to the exact 4construction and operation .shown and described, yand accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A pipe protector comprising an .arcuate C-shaped body of 'a resiliently deformable material for compressively embracing and protectively enclosing the threaded extremity of a pipe, a quick releasable fastener joining the ends of said body and operable to circumferentially tension and release said ends, said fastener being mounted and recessed within said body whereby in the tensioned position of the fastener and body all portions of the former Iare recessed into the latter, said fastener including an anchor bracket yand a lever bracket each recessed and tixedly secured in an adjacent end of said body, an anchor link secured to said anchor bracket and a latch lever pivoted to said lever bra-cket, said anchor link having an over-center pivot connection to said latch lever, a suspending slot -in said latch lever.

2. A pipe protector comprising an arcuate C-shaped body of a resiliently deformable material for compressively embracing and protectively enclosing the threaded extremity of a pipe, a quick releasable fastener joining the ends of said body and operable to circumferentially tension and release said ends, said fastener being mounted and recessed within said body whereby in the tensioned position of the fastener Iand body all portions of the former are recessed into the latter, said fastener including an anchor bracket and a lever bracket each recessed and xedly secured in an adjacent end of said body, an anchor link secured to said anchor bracket and a latch lever pivoted to said lever bracket, said anchor link having an over-center pivot connection to said latch lever, said lever bracket being U-shaped in cross-section with a base plate and side walls, said body having a circumferentially extending channel at one end in which said bracket is received, pivot means securing said latch lever to said bracket.

3. The combination of cl-aim 2 wherein said pivot means comprises parallel ears upstanding from said said base plate between said side walls, said latch lever being pivoted between said ears.

4. The combination of claim 3 wherein said anchor link includes side arms which embrace said ears in the closed position of said fastener.

5. A pipe protector lcomprising an arcuate C-shaped body of a resiliently deformable material for compressively embracing and protectively enclosing the threaded extremity of a pipe, a quick releasable fastener joining the ends of said body and operable to circumferentially tension and release said ends, said fastener being mounted and recessed within said body whereby in the tensioned position of the fastener and body all portions of the former are recessed into the latter, said fastener including an anchor bracket `and a lever bracket each recessed and xedly secured in an adjacent end of said body, an anchor link secured to said anchor lbracket and a latch lever pivoted to said lever bracket, said anchor link having an over-center pivot connection to said latch lever, said lever bracket being U-shaped in `cross-section With a base plate and side walls, said body having a circumferentially extending lchannel at one end thereof, said base plate and side walls being embedded respectively in the bottom `and sides of said channel for reinforcing said body.

References Cited by the Examiner UNITED STATES PATENTS 440,168 11/1890 Kurtz 13S-96 Adams.

Engstrom 138-96 Smith 138-96 X Smith 138-96 X Williams et al. 308--4 Brown 166-46 Peter 138--96 Hauk et al. 138-96 Allan 166-'46 10 LAVERN'E D. GEIGER, Primary Examiner.

LEWIS I. LENNY, lEDWARD V. BENHAM, Examiners. 

1. A PIPE PROTECTOR COMPRISING AN ARCUATE C-SHAPED BODY OF A RESILIENTLY DEFORMABLE MATERIAL FOR COMPRESSIVELY EMBRACING A PROTECTIVELY ENCLOSING THE THREADED EXTREMITY OF SAID PIPE, A QUICK RELEASABLE FASTENER JOINING THE ENDS OF SAID BODY AND OPERABLE TO CIRCUMFERENTIALLY TENSION AND RELEASE SAID ENDS, SAID FASTENER BEING MOUNTED AND RECESSED WITHIN SAID BODY WHEREBY IN THE TENSIONED POSITION OF THE FASTENER AND BODY ALL PORTIONS OF THE FORMER ARE RECESSED INTO THE LATTER, SAID FASTENER INCLUDING AN ANCHOR BRACKET AND A LEVER BRACKET EACH RECESSED AND FIXEDLY SECURED IN AN ADJACENT END OF SAID BODY, AN ANCHOR LINK SECURED TO SAID ANCHOR BRACKET AND A LATCH LEVER PIVOTED TO SAID LEVER BRACKET, SAID ANCHOR LINK HAVING AN OVER-CENTER PIVOT CONNECTION TO SAID LATCH LEVER, A SUSPENDING SLOT IN SAID LATCH LEVER. 